shtab v1.11.0 stable

• 📚 add helpful headers (instructions to end-users) to generated scripts (#253)
• ⚙️ add complex developer examples (#253)
• ⏪ support bash completion mid-command (#248 <- #116)
• 🗃️ bash: drop global compopt -o filenames (#250 <- #67)
• 🍂 fix fallbacks (#252)
  • 🥇 zsh: metavar overrides dest
  • 🍥 zsh & fish: description overrides help, rewrap descriptions
  • 🤫 tcsh: respect help=SUPPRESS
  • 😖 fix choices: dict without confusing with subparsers (#214 -> #220)
  • ⏩ forward-compatible with python/cpython#67037
• 📚 update FAQs (#252 <- #190, #169, #105)
• 🔀 fix zsh positional ordering (#251 <- #123)
• 🧹 misc tidying